From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from BL2PR02CU003.outbound.protection.outlook.com (mail-eastusazon11011066.outbound.protection.outlook.com [52.101.52.66]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 695503E4C87; Fri, 26 Jun 2026 12:47:55 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=fail smtp.client-ip=52.101.52.66 ARC-Seal:i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1782478080; cv=fail; b=UgjskUEHsXk6VkR6kncHh39NgbbgYkt6LcN+Op6g+B1DPqRyBH2ERCHJVKcFrJaJXZTMj7hQb6m9vSblT5mY3L+sqwPNPR7l3LFP7yPQFr14shSHkgeMCaMMRSDdnzGxLMvPS80D48wSovcycZn81n20HJ7NrUnr9n604RuWuPk= ARC-Message-Signature:i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1782478080; c=relaxed/simple; bh=Q8xFtsb5mxnTEwRkJdomwc+jgVXRCiUnvfvp2yh2Pvo=; h=Message-ID:Date:Subject:To:Cc:References:From:In-Reply-To: Content-Type:MIME-Version; b=JAmvLuKmiMC4uHf6DIEwC1/4R4gbuoIVUDPwV1dl7nzkn9lFFbKKyMqPX4GqhEgDTQ4IsnbghjUAGdeXRMUmjQrjrwr0U1g5TWyz0Ej8W81p8hMcFL/vLfC7B859xIDkEc3IykaQLbgLavO/Qqxniev9AnpOBDfEvD6iksgp1Cg= ARC-Authentication-Results:i=2; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=amd.com; spf=fail smtp.mailfrom=amd.com; dkim=pass (1024-bit key) header.d=amd.com header.i=@amd.com header.b=QEsM/T5N; arc=fail smtp.client-ip=52.101.52.66 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=amd.com Authentication-Results: smtp.subspace.kernel.org; spf=fail smtp.mailfrom=amd.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=amd.com header.i=@amd.com header.b="QEsM/T5N" ARC-Seal: i=1; a=rsa-sha256; s=arcselector10001; d=microsoft.com; cv=none; b=gfrh1rt5NtjOYn5ra0qo9ayqwGvMu6ty8ffz/QGWdytYFbCdAgy7EnXBqihYfrT8t9kel3Lu89ycYLF5fUXNTTql1kJyC6GXSE6xRMwXxOrF6jpqaw+o6PC9E1hs8v4MQSYT2nWfWoDuHqKskgEQ/dUaqA6xxynBgmHUk2GKU9TUcjuq+SKnBiJTHlFQF5TumXIeYjHpWd9YC5j3BRDbS3W83qLJ3lKosZClBkoT5VmvsAiPMMiW+ecKsjI7flIcQNWMFbUvcimDsDMmjHCOAeA8xASMXyQJoyoU/XZ/BANjceG6xPM9kTw/1tViMmHDSP535wjz+DGKY7MuQRdzuA== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=microsoft.com; s=arcselector10001; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-AntiSpam-MessageData-ChunkCount:X-MS-Exchange-AntiSpam-MessageData-0:X-MS-Exchange-AntiSpam-MessageData-1; bh=z9AUdNGNKupZUUBrcI+nBGbrh6vdXHBFVgrpJjCDwCg=; b=j1MvD19mS7SlmJF/T+1CdhB3p/45gxmpd5fFnntcbbh0o8aeKY2rns1w458R9MFI3VbqSXXjNZNaKchU8D0O330+1nS8IXa/yQTo9HmluJUz2vjUcEDIoTfetYkHr42p2b/SIi9tGV1icB8KWMZiXJSeYnSBJ9JaDuxBLCsCUr9Dr2mjiRvSeowh71SAHsBCqo7wsKFqZykOzMISUBv4vs12Th//a+xGuM7KDlrspzKu5NmI3xis/chQLrSRAQ/pveVECx9w9XdignsozSCPEiiRW0h2tOi53VBQQPpqbsjEuxrIla6PAFYQECvLsidK8pf81QEbPgg2ap9CH5jrWw== ARC-Authentication-Results: i=1; mx.microsoft.com 1; spf=pass smtp.mailfrom=amd.com; dmarc=pass action=none header.from=amd.com; dkim=pass header.d=amd.com; arc=none DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=amd.com; s=selector1; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-SenderADCheck; bh=z9AUdNGNKupZUUBrcI+nBGbrh6vdXHBFVgrpJjCDwCg=; b=QEsM/T5NknEmWfFhKOv7OSBJ86r+EGIPujDOOVIEh1T3Xln/hdoexIKqY9xLtdtvrEUZoN76STCxQORY8DqCktyzSx59nPJoLnnaECCzDk9vl0NZ3R9ulgq60GMIKzZc8QFYLT1p3ucXGsRrIvzhFsIBnTGXCPmKT3nLSn2NN/I= Authentication-Results: dkim=none (message not signed) header.d=none;dmarc=none action=none header.from=amd.com; Received: from PH7PR12MB5685.namprd12.prod.outlook.com (2603:10b6:510:13c::22) by IA1PR12MB8190.namprd12.prod.outlook.com (2603:10b6:208:3f2::7) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.21.159.17; Fri, 26 Jun 2026 12:47:52 +0000 Received: from PH7PR12MB5685.namprd12.prod.outlook.com ([fe80::ce69:cfae:774d:a65c]) by PH7PR12MB5685.namprd12.prod.outlook.com ([fe80::ce69:cfae:774d:a65c%5]) with mapi id 15.21.0159.016; Fri, 26 Jun 2026 12:47:52 +0000 Message-ID: <5180c887-c879-440f-a58b-1cad96b7abb1@amd.com> Date: Fri, 26 Jun 2026 14:47:47 +0200 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH] fix: dma-buf: unwrap_merge_complex: dma_fence_get_stub reference leaked on all paths To: WenTao Liang , sumit.semwal@linaro.org Cc: linux-media@vger.kernel.org, dri-devel@lists.freedesktop.org, linaro-mm-sig@lists.linaro.org, linux-kernel@vger.kernel.org, stable@vger.kernel.org References: <20260626122836.35856-1-vulab@iscas.ac.cn> Content-Language: en-US From: =?UTF-8?Q?Christian_K=C3=B6nig?= In-Reply-To: <20260626122836.35856-1-vulab@iscas.ac.cn> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-ClientProxiedBy: BL1PR13CA0422.namprd13.prod.outlook.com (2603:10b6:208:2c3::7) To PH7PR12MB5685.namprd12.prod.outlook.com (2603:10b6:510:13c::22) Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: PH7PR12MB5685:EE_|IA1PR12MB8190:EE_ X-MS-Office365-Filtering-Correlation-Id: 0205992c-ea4e-4deb-9603-08ded38122a5 X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0;ARA:13230040|376014|23010399003|1800799024|366016|18002099003|22082099003|11063799006|56012099006; X-Microsoft-Antispam-Message-Info: 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 X-Forefront-Antispam-Report: CIP:255.255.255.255;CTRY:;LANG:en;SCL:1;SRV:;IPV:NLI;SFV:NSPM;H:PH7PR12MB5685.namprd12.prod.outlook.com;PTR:;CAT:NONE;SFS:(13230040)(376014)(23010399003)(1800799024)(366016)(18002099003)(22082099003)(11063799006)(56012099006);DIR:OUT;SFP:1101; X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?utf-8?B?Vk41azdEUTFtRVJXNTZxTk5oZSsyNkdpWVF3aUZOTGtUQ0tyZDN3MUMvQkFB?= =?utf-8?B?WHZXalAvdlg0Nk9QNzZHYllwQldjMDBFNmdyTEdZYkJNUXZ4aDA2a0plblRF?= =?utf-8?B?SWlkbTUvR3lOVzdyZm8zZmIyUHZrOG9zYTBCL0tVaXRjTmgvSjEwaTB5alFw?= =?utf-8?B?M1B0c2NIQTdGUTJBaXlMOGVlWHd3NW4zYXgwTm1BbTRyc0VoNk0xeHZiQ29B?= =?utf-8?B?bTY3S09scGhaemZyM1A3aVVhWGJ2NzdDZXk1K1ZXYURKQk1aMEZhMHBkRDRo?= =?utf-8?B?WDU3M1YxRXFlYmJlR2YzcWhiQjFSdElLRVQwNE1aT0RLRk4ySTNGdWtDa01o?= =?utf-8?B?djBxamFnZXV4OS9VeUN3TXZzNWdMZndnZXRlR1NFMTQycWV4RERLSytmU0xM?= =?utf-8?B?QjJPUHN0eno1ZWVHRVdPSWpTalBFZHMycGowaHJFRHIyYkxxcS9SZGtDTmhK?= =?utf-8?B?dEEwK3kyZ29nTm1VdjZLTk5ncFpncXowZ013eHl2MTNSSU1YZHozNFF5MUpK?= =?utf-8?B?TUQvWVBwZVVHUkd1VklFdWpBbmdhR2lBaDRQQlluMUprSnc1b0NLbGhYeUhK?= =?utf-8?B?bmdsdXpTcEZId1FjZnMydGJKWjVKdFVhRXpyTExCQjZXSmovcFlkVmIxRzU1?= =?utf-8?B?bmdFSG5XdTV6cFRoYjZFUjgyejBPSXlTdUhqUUthMGhuTHlSS3ExVFpxNTNI?= =?utf-8?B?L2paOWYzUXp0OHpnMml1NGRsQkp5NkRsWlBUNHE0aEQzdElQYWlLeEl3ZEFq?= =?utf-8?B?NEo5MDlrcFVpWTNsWnFtNEpuWVZraXJpeGRYSEIxa1lHU3JKNFNDamt1d3Vp?= =?utf-8?B?a1NHM0x3enp3OEVEczBWbzMrQ1JOeHhpMEN6TGl0TklndmtVaVc3MHpFeVJx?= =?utf-8?B?eWFQZWRBbE8wNldnQXZoTlgyZitsNFYvVEprSHpjLzRkWDlQWS9QU3BDaFBo?= =?utf-8?B?T3R6QlJkNDBzWEMrdUZiOTA1WW1rNVRnRHhvN0dUdjF0RGVCaXowUXRnWVdF?= =?utf-8?B?N0JKNXAxeHlWNnVpSVl5QzQwUkRjaFZxV3lCTklKd2VvNFRRRkpIenBlQjJW?= =?utf-8?B?ekhZTzdFYkhOVUR6czhVT0RlRWlvalZMV0lod3FzV2pLdjQ3UGs4dUhudEdN?= =?utf-8?B?T2JEeURjSDdFM2VxOTdJcFdqUUhBUG5CQlAxR3Zmb1orbkpyWEQzcUhMQW5x?= =?utf-8?B?ZUtqWUV4a1dkMVNOTGNxNFRuc1N1Z2FIeDJBZVAvUmhzM2hRMC9MQ3BYQjBY?= =?utf-8?B?WUFTbmxtRGdJa0JGY3RrNVpiOVErZ3QvWisvNU9nY2Y0NEN6S05JRDFzeXox?= =?utf-8?B?d0dsdk9ubEg3SWsvMUFybEVXeHM2c0pzQ2FBeHFabmc5bGlCVmFPcHNPby92?= =?utf-8?B?ekN5T2FhUWJuRzdISml0RFNMbVVTNjlGSXo0d1VhaXUzYkdIQ1NMQWpWT01H?= =?utf-8?B?M1JOM2ZCY2JHM01MN1A2cWorWEQ4TXF1YllQc2JVYXVIc3ErZnVZcHN2L2lt?= =?utf-8?B?R2tiV2ZUNUZtc2M5c3N3N0J4Qm92LzhuUG4vbEFmejF1TncyTndLSFNqcXVO?= =?utf-8?B?b1NWTGVLbE9rRUJmRUZqQXluSEdWZy9pUU5BWCt3YndKSGVQNDI4bXBjdFpF?= =?utf-8?B?RTYvOUJ2dTNQaHgzbEtKNitabGgxUEYrSWYxbldScU54OC95YVFBdGtBSUJM?= =?utf-8?B?d1RhLzdXbWxJd1Z2cHY5cW5DZndRUGhvaDV3elFCcWR0c05kMm54NkxBb2xP?= =?utf-8?B?bWFOQjFLNTV0SUJMY2g4NHFTbU4zcFliRUJleEpFeFcyUEIzRUYxMnNYaEh4?= =?utf-8?B?bDZ2MnQrUmZJOEdZSFRzWXZtaldJMzM3MjFVZHF6UWV2ak9sWlJNS1pyR09y?= =?utf-8?B?Tm5ualdteS9PaWdXd1VHNEZ2QVdXMUlRbUJ0dkdJZnpxUEhrVHdMbnUwMnF1?= =?utf-8?B?aHlXWkZqS2NJakFIL3FTSGpDRFlDMEtveTE5SEp5Zm5PZFNpcXZVWmFiWmd5?= =?utf-8?B?ZzQrNk1yTWMyR2FacmpZSGxKNEVNM3UwWS9ucUIvV2ExWFcxREprbzcxNWQw?= =?utf-8?B?T1hKd3JtNy82SmQ1b1FJNzBiV3YzK3JBdTJLWEt4Ty9URGFRRlRuTzNRT1J5?= =?utf-8?B?cVpNbENLVmRWV1YxcElZdXljTm1kMWIvWnZOLzRRUHJLaTFCMzBnVFVkNk45?= =?utf-8?B?VENVcUdFQjFOWnlMV2NIYUZFc3hMR0cvQVdId2F4ZjNrQ3pNcnpPNkxvZjVC?= =?utf-8?B?WityK1VINUlBdWpLSnJkc2czS2hQQVN5NklPWkZjU0lkcUdpVklTT0NscGs4?= =?utf-8?Q?BeMVp4kIr1lpkTxYoD?= X-OriginatorOrg: amd.com X-MS-Exchange-CrossTenant-Network-Message-Id: 0205992c-ea4e-4deb-9603-08ded38122a5 X-MS-Exchange-CrossTenant-AuthSource: PH7PR12MB5685.namprd12.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 26 Jun 2026 12:47:52.0013 (UTC) X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted X-MS-Exchange-CrossTenant-Id: 3dd8961f-e488-4e60-8e11-a82d994e183d X-MS-Exchange-CrossTenant-MailboxType: HOSTED X-MS-Exchange-CrossTenant-UserPrincipalName: jWwoNMEPf/qfC0KdJEV1qogXMRd4brK28gt64RcFe0u7J3kE9PC21ZK5yJTc+/8g X-MS-Exchange-Transport-CrossTenantHeadersStamped: IA1PR12MB8190 On 6/26/26 14:28, WenTao Liang wrote: > dma_fence_get_stub() acquires an extra reference on the global stub > fence, but this reference is never released on any execution path. The > stub fence is filtered out inside dma_fence_unwrap_merge (already > signaled), so the extra reference is never consumed. Both success and > error paths fail to call dma_fence_put on the stub. > > Cc: stable@vger.kernel.org > Fixes: 245a4a7b531c ("dma-buf: generalize dma_fence unwrap & merging v3") Just drop that, the stub fence is a global dummy and leaking reference to it is harmless. But just in case somebody uses this code as blueprint for this own implementation we should probably clean it up. > Signed-off-by: WenTao Liang Reviewed-by: Christian König > --- > drivers/dma-buf/st-dma-fence-unwrap.c | 11 +++++++---- > 1 file changed, 7 insertions(+), 4 deletions(-) > > diff --git a/drivers/dma-buf/st-dma-fence-unwrap.c b/drivers/dma-buf/st-dma-fence-unwrap.c > index 72ca632e3981..b9ed85570211 100644 > --- a/drivers/dma-buf/st-dma-fence-unwrap.c > +++ b/drivers/dma-buf/st-dma-fence-unwrap.c > @@ -483,7 +483,7 @@ static int unwrap_merge_order(void *arg) > > static int unwrap_merge_complex(void *arg) > { > - struct dma_fence *fence, *f1, *f2, *f3, *f4, *f5; > + struct dma_fence *fence, *f1, *f2, *f3, *f4, *f5, *stub; > struct dma_fence_unwrap iter; > int err = -ENOMEM; > > @@ -508,10 +508,11 @@ static int unwrap_merge_complex(void *arg) > if (!f4) > goto error_put_f3; > > + stub = dma_fence_get_stub(); > /* Signaled fences should be filtered, the two arrays merged. */ > - f5 = dma_fence_unwrap_merge(f3, f4, dma_fence_get_stub()); > + f5 = dma_fence_unwrap_merge(f3, f4, stub); > if (!f5) > - goto error_put_f4; > + goto error_put_stub; > > err = 0; > dma_fence_unwrap_for_each(fence, &iter, f5) { > @@ -532,8 +533,10 @@ static int unwrap_merge_complex(void *arg) > err = -EINVAL; > } > > + dma_fence_put(stub); > dma_fence_put(f5); > -error_put_f4: > +error_put_stub: > + dma_fence_put(stub); > dma_fence_put(f4); > error_put_f3: > dma_fence_put(f3);